mash: Use the new mus drag and drop API to get drag working in mash.

services/ui/ws/window_tree.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "services/ui/ws/window_tree.h"
 
 #include <stddef.h>
 
 #include <utility>
 
@@ skipping 1487 matching lines @@
 void WindowTree::GetCursorLocationMemory(
     const GetCursorLocationMemoryCallback& callback) {
   callback.Run(
       window_server_->display_manager()->GetUserDisplayManager(user_id_)->
       GetCursorLocationMemory());
 }
 
 void WindowTree::PerformDragDrop(
     uint32_t change_id,
     Id source_window_id,
-    int32_t drag_pointer,
     mojo::Map<mojo::String, mojo::Array<uint8_t>> drag_data,
     uint32_t drag_operation) {
   ServerWindow* window = GetWindowByClientId(ClientWindowId(source_window_id));
   bool success = window && access_policy_->CanInitiateDragLoop(window);
   if (!success || !ShouldRouteToWindowManager(window)) {
     // We need to fail this move loop change, otherwise the client will just be
     // waiting for |change_id|.
     DVLOG(1) << "PerformDragDrop failed (access denied).";
     OnChangeCompleted(change_id, false);
     return;
@@ skipping 16 matching lines @@
   }
 
   // TODO(erg): Dealing with |drag_representation| is hard, so we're going to
   // deal with that later.
 
   // Here, we need to dramatically change how the mouse pointer works. Once
   // we've started a drag drop operation, cursor events don't go to windows as
   // normal.
   WindowManagerState* wms = display_root->window_manager_state();
   window_server_->StartDragLoop(change_id, window, this);
-  wms->SetDragDropSourceWindow(this, window, this, drag_pointer,
-                               std::move(drag_data), drag_operation);
+  wms->SetDragDropSourceWindow(this, window, this, std::move(drag_data),
+                               drag_operation);
 }
 
 void WindowTree::CancelDragDrop(Id window_id) {
   ServerWindow* window = GetWindowByClientId(ClientWindowId(window_id));
   if (!window) {
     DVLOG(1) << "CancelDragDrop failed (no window)";
     return;
   }
 
   if (window != window_server_->GetCurrentDragLoopWindow()) {
@@ skipping 350 matching lines @@
   client()->OnCompleteDrop(client_window_id.id, event_flags, cursor_offset,
                            effect_bitmask, callback);
 }
 
 void WindowTree::PerformOnDragDropDone() {
   client()->OnDragDropDone();
 }
 
 }  // namespace ws
 }  // namespace ui